15厘米太阳射电望远镜增益运算放大器的制作与调试

本文介绍了１５厘米太阳射电望远镜增益运算放大器的结构原理，调试检测及测试结果。     

Comparisons of Three-Dimensional Variational Data Assimilation and Model Output Statistics in Improving Atmospheric Chemistry Forecasts

Atmospheric chemistry models usually perform badly in forecasting wintertime air pollution because of their uncertainties. Generally, such uncertainties can be decreased effectively by techniques such as data assimilation(DA) and model output statistics(MOS). However, the relative importance and combined effects of the two techniques have not been clarified. Here,a one-month air quality forecast with the Weather Research and Forecasting-Chemistry(WRF-Chem) model was carried out in a virtually operational setup focusing on Hebei Province, China. Meanwhile, three-dimensional variational(3 DVar) DA and MOS based on one-dimensional Kalman filtering were implemented separately and simultaneously to investigate their performance in improving the model forecast. Comparison with observations shows that the chemistry forecast with MOS outperforms that with 3 DVar DA, which could be seen in all the species tested over the whole 72 forecast hours. Combined use of both techniques does not guarantee a better forecast than MOS only, with the improvements and degradations being small and appearing rather randomly. Results indicate that the implementation of MOS is more suitable than 3 DVar DA in improving the operational forecasting ability of WRF-Chem.     

黄河流域气候监测服务系统设计与应用

针对黄河流域气候监测业务比较薄弱,缺乏有效业务平台支撑的情况,河南省气候中心开展了黄河流域气候监测服务系统建设。建立了包括黄河流域气象台站历史资料与实时资料的流域气候监测资料库,开发了黄河流域气候监测服务软件,实现了任意时段、任意流域气温、降水、气象干旱的资料计算与提取,实现了暴雨日数、最大日降水量、降水日数、极端高温、极端低温、高温日数、低温日数等计算,实现了对任意时段、任意站点(或任意省份、任意流域)气温、降水随时间变化的线性趋势分析,基于Surfer自动化技术的图形绘制模块可以进行降水量实况图、降水距平百分率图、气温实况图、气温距平图、气象干旱实况图、暴雨日数图、高温日数图、低温日数图等的制作和输出,实现了业务产品自动生成与分发。整个系统功能实用、使用方便,提高了业务人员工作效率,增强了黄河流域气候监测服务能力和水平,为黄河流域气候监测服务提供了重要的技术支撑,在黄河流域气候监测、决策气象服务等工作中得到了较好的应用。     

Symbiodinium (internal transcribed spacer 2) diversity in the coral host Agaricia lamarcki (Cnidaria: Scleractinia) between shallow and mesophotic reefs in the Northern Caribbean (20–70 m)

This study investigated differences in Symbiodinium diversity in the scleractinian coral species Agaricia lamarcki between shallow (20–25 m) and mesophotic (50–70 m) depths in the Northern Caribbean. Corals were sampled in each of four shallow sites (20–25 m; n = 18) and three mesophotic sites (50–70 m; n = 18) from Mona Island (Puerto Rico) and the US Virgin Islands during a mesophotic exploratory cruise and from the La Parguera shelf edge, off Southwestern Puerto Rico. Symbiodinium diversity was assessed using internal transcribed spacer 2 sequences clustered into operational taxonomic units (OTUs). Clustering resulted in eight clade C OTUs and one clade D OTU. Of these, there were three common Symbiodinium OTUs consisting of C3 and D1a.N14 in shallow reefs and C11.N4 in mesophotic reefs. Statistical tests (permutational multivariate analysis of variance and analysis of similarity) showed significant differences between clade C Symbiodinium OTUs in A. lamarcki colonies located at shallow and mesophotic depths, indicating symbiont zonation. Symbiodinium diversity in A. lamarcki from the Northern Caribbean is comparable to previous reports in the Southern Caribbean for this species. This is the first report of the thermal tolerant species Symbiodinium trenchii (D1a) in A. lamarcki.     

新型射流式元件结构设计与试验研究

射流式液动锤由于其具有钻进效率高、钻进深度不受限制等优点被成功应用于油气钻井领域。然而由于射流元件在复杂受力条件下极易破损,严重制约了射流式液动锤的使用寿命。为解决此问题,对射流式液动锤射流元件受力情况进行了数值模拟分析,通过分析射流元件内部应力场分布情况,得出了射流元件破损机理,并设计了新型两体式射流元件。模拟分析研究表明,采用新型两体式射流元件可将元件内最大应力值降低一个数量级,使射流元件受力情况明显改善,可有效地提高其使用寿命。     

The need for operational reasoning in data‐driven rating curve prediction of suspended sediment

The use of data‐driven modelling techniques to deliver improved suspended sediment rating curves has received considerable interest in recent years. Studies indicate an increased level of performance over traditional approaches when such techniques are adopted. However, closer scrutiny reveals that, unlike their traditional counterparts, data‐driven solutions commonly include lagged sediment data as model inputs, and this seriously limits their operational application. In this paper, we argue the need for a greater degree of operational reasoning underpinning data‐driven rating curve solutions and demonstrate how incorrect conclusions about the performance of a data‐driven modelling technique can be reached when the model solution is based upon operationally invalid input combinations. We exemplify the problem through the re‐analysis and augmentation of a recent and typical published study, which uses gene expression programming to model the rating curve. We compare and contrast the previously published solutions, whose inputs negate their operational application, with a range of newly developed and directly comparable traditional and data‐driven solutions, which do have operational value. Results clearly demonstrate that the performance benefits of the published gene expression programming solutions are dependent on the inclusion of operationally limiting, lagged data inputs. Indeed, when operationally inapplicable input combinations are discounted from the models and the analysis is repeated, gene expression programming fails to perform as well as many simpler, more standard multiple linear regression, piecewise linear regression and neural network counterparts. The potential for overstatement of the benefits of the data‐driven paradigm in rating curve studies is thus highlighted. Copyright © 2011 John Wiley & Sons, Ltd.     

基于Web Service的气象服务产品传真发布技术

介绍了宁波市气象服务产品传真发布系统的设计思路、技术框架、关键技术和应用情况。针对目前气象服务产品多使用网页方式展现的现状,开发了网页传真功能,通过Web Service方式实现了传真发布手段与气象服务产品的无缝衔接,提供了发送记录、回执查询和失败重发等功能;针对预警信号等服务产品传真对象相对固定的特点,研发了各类产品传真默认信息配置模块,实现服务产品与默认传真收件人的动态绑定。该系统高达100路/min的发送效率,极大地提高了预警发布的时效性,在气象防灾减灾中发挥了重要作用。     

雷电临近预警系统的运行试验

介绍了中国气象科学研究院研发的雷电临近预警系统(CAMSLNWS)在北京地区开展的业务运行试验.通过运行测试以及预警结果与闪电监测结果的对比评估,表明:CAMS.LNWS能够稳定运行,定时读取多种探测资料、自动生成并循环显示雷电发生概率、雷电活动区域移动趋势和重点区域雷电危险度等级三种雷电临近预警产品;CAMS.LNWS的雷电发生概率预警产品具有较高的命中率,能够较好地对0～30min内可能发生闪电的区域进行有效预警;随着预警时间的延长,CAMS.LNWS的预警效果会有所降低.     

多普勒天气雷达数据管理及运行保障系统

围绕多普勒天气雷达运行中存在的突出问题,开发了"新一代天气雷达基数据管理系统"、"新一代天气雷达二次产品浏览系统"、"新一代天气雷达远程终端监控系统"3个子系统,分别运行于不同的雷达终端上,实现了雷达基数据压缩管理、二次产品共享浏览、远程终端监控等功能。每个子系统均为一个特定的任务设计,针对性强,解决了该领域的突出问题。系统使用多项成熟的软件开发技术,涉及到软件开发的诸多方面。多线程、目录监控、远程控制、图像缓存、内存文件传输等核心技术的使用,确保了系统的稳定和高效运行。